There is a bug at the menu, you can see it at https://www.tophair.gr. The menu is completely broken and even though i changed the main menu, those changes are not reflected at the layout.
Your menu is too long, the menu does not assume having so many items, You need to consider the option to reduce the number of items on the menu. Try to create sub menu or mega menu items for a long menu.
For changing the menu, Navigate to woodmart > Header Builder > edit Current Header > Configure main menu settings and select the menu which you want.